1. Field of the Invention
The invention relates to a portable computer, and more particularly, to a touch pad apparatus for use as an input device in a portable computer
2. Background of the Related Art
A touch pad apparatus or a pointing stick is used as a pointing device which may be used instead of a mouse when a portable computer, such as a notebook computer, is transported. FIG. 1 shows a portable computer which is provided with a conventional touch pad apparatus.
As shown in FIG. 1, a related portable computer generally comprises a main body 1 and a display 3. The display 3 is connected to both rear side edges of the main body 1 by hinges 5. Thus, the display 3 may be seated on an upper surface of the main body 1 or unfolded at a predetermined angle, as shown in FIG. 1. The display 3 is provided with a display screen 3,′ such as a liquid crystal display panel.
The upper surface of the main body 1 is defined by a keydeck 7. A plurality of keys 8 are arranged in the keydeck 7. A plurality of the keys 8 are arranged in several rows on the upper surface of the main body 1. A front end of an upper surface of the keydeck 7 defines an armrest 9 on which user's hands are seated when the user types with the keys 8. A touch pad apparatus 10 is provided at a center of the armrest 9.
FIG. 1A is a detailed view of a portion of the related art portable computer of FIG. 1. As shown in FIG. 1A, the keydeck 7 is provided with a pad vent hole 11 and a button vent hole 12. The pad vent hole 11 is substantially in the shape of a quadrangle. The button vent hole 12 is formed in the keydeck 7 in front of the pad vent hole 11.
A touch pad 13 is seated in the pad vent hole 11 from below the keydeck 7. The touch pad 13 receives information regarding position, to which a user wishes to point, by sensing a touch of a user's finger. The touch pad 13 is provided with a cable 14 and a connector 15 in order to be electrically connected to other devices.
A touch pad housing 16 is provided in order to fix the touch pad 13 to the keydeck 7. The touch pad housing 16 is formed with a seating step 16′, in which an edge of a lower surface of the touch pad 13 is seated.
The touch pad housing 16 is provided with fastening bosses 17 for mounting the touch pad housing 16 to the keydeck 7. Each of the fastening bosses 17 is formed with a fastening hole 17h through which a screw for fastening the touch pad housing 16 to the keydeck 7 passes.
A button 18 is provided at a position corresponding to the button vent hole 12 in a front end of the touch pad housing 16. The button 18 serves to select the position information input through the touch pad 13. A pad substrate 19 is provided with a variety of parts for operating the touch pad 13, such as a switch 19′ and the like driven by the button 18.
However, the aforementioned related art portable computer has at least the following problems.
First, the touch pad housing 16 must be used in order to fasten the touch pad 13 to the keydeck 7 and position it in the pad vent hole 11. In addition, the pad substrate 19 additionally must be mounted under the touch pad housing 16. Thus, there is the problem that the main body 1 is relatively thick at a portion at which the touch pad 13 is provided. That is, a relatively large space for installing the touch pad apparatus 10 is required.
Further, if the touch pad apparatus 10 is installed within the front end of the main body 1, the inner space of the portable computer is small. Thus, there is the problem that parts for adding additional functions cannot be installed therein.